Use of scintillating materials in scanning beam proton therapy have been limited to two-dimensional (“2D”) scintillation. Three dimensional (“3D”) scintillation has been only used in brachytherapy applications using radioactive sources to study the dosimetric properties of different scintillating solutions with the aim of developing water equivalent dosimeter media at the lower energies suitable for use with commonly used radioactive sources. Such systems have not been used in intensity modulated radiation therapy (“IMRT”) beams, scanning proton particles and beams, and/or to characterize the intensity and energy modulated proton therapy beam. Fast, accurate and efficient 3D dosage measurements must be made to ensure patient-specific quality assurance.